all 501(c)(3) organization's are required to file taxes, but that doesn't mean that they are made available to the public. for instance, it is optional for religious organization's to make their tax forms available for public inspection. and religous organization's take advantage of that. but if you are still interested in their financials, many release an annual report each year detailing how their money was spent, you can use that to fill in many of the blanks.  you can also just ask them, they may not tell you, but you can ask.